The Maine Public Utilities Commission said Tuesday it would launch a formal investigation into Central Maine Power’s billing and metering systems following customer complaints about skyrocketing bills and poor quality service.

PUC Chairman Mark Vannoy and Commissioners R. Bruce Williamson and Randall Davis agreed to start a “technical forensic audit” to look expressly at metering and billing issues that have arisen over the past several months. Vannoy said it could take a while to get an auditor and conduct the audit because of the technical nature of CMP’s system.

On Feb. 27, the commission launched a summary investigation to collect data on whether all issues with CMP’s new billing system have been identified and whether the utility is responding to and resolving customer calls reasonably. The PUC cited CMP’s new billing system, launched as Maine was hit with the historic October wind storm, a cold snap and electricity supply price increases, as possible reasons for the high bills.

The summary investigation still is in its early stages. Vannoy said the audit information will be added to the summary investigation to speed up the discovery process.

All three commissioners approved the audit.

The PUC will issue a request for proposals with a detailed scope for discovery as it searches for an auditor with technical expertise.

“I approve [checking] customer billing from the meter, whether it’s a smart [digital] or analog meter, all the way through to the creation and delivery of a customer bill, which includes both financial and usage information,” Davis said.

Tuesday afternoon, CMP President and CEO Doug Herling said he welcomed the PUC’s audit and that CMP is conducting its own review.

“We are conducting our own comprehensive review of the complaints to determine what the underlying causes were for the increases. Any detected errors will be fixed and those customers will be made whole,” he said in a written statement.

“Our customers want their lights to turn on. They want their rates to be as low as possible. And they want us to help them when problems arise,” he said. “We understand and to that end, we are working hard to analyze each complaint.”

He said CMP has trained a new team of dedicated experts to work on customer issues and ensure that complaints are reviewed promptly and thoroughly.

“That team is currently working through our entire list of complaints and resolving outstanding inquiries as quickly as possible,” he said.

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